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iglide® A290 - Material data

Materials table

General features Unit iglide® A290 Test method
Density g/cm³ 1,41
Color White
Max. moisture absorption at 73° F / 50% R. H. % weight 1,7 DIN 53495
Max. moisture absorption % weight 7,3
Coefficient of surface friction, dynamic, against steel µ 0,13 - 0,40
p x v value, max. (dry) psi x fpm 6,600

Mechanical properties
Modulus of elasticity psi 1,276,000 DIN 53457
Tensile strength at 68° F psi 36,260 DIN 53452
Compressive strength psi 13,200
Permissible static surface pressure (68° F) psi 10,150
Shore D hardness 88 DIN 53505

Physical and thermal properties
Upper long-term application temperature °F 284
Upper short-term application temperature °F 356
Lower application temperature °F -40
Thermal conductivity [W/m x K] 0,24 ASTM C 177
Coefficient of thermal expansion (at 73°F) [K-1 x 10-5 ] 7 DIN 53752

Electrical properties
Specific volume resistance Ωcm > 1011 DIN IEC 93
Surface resistance Ω > 1011 DIN 53482


Permitted p x v values

For iglide® A290 plastic bushings running dry against a steel shaft, at 68° F.


Figure 9.2: Deformation under load and temperatures

Surface pressure

iglide® A290 plastic bushings are an advanced development for the use in food and pharmaceutical industry. Compared to the bushings made of iglide® A200, the tribological properties could be significantly improved.

iglide® A290 plastic bushings have a recommended maximum surface pressure of 10,150 psi. At this load, the deformation at room temperature is only 2.5%. A plastic deformation is close to zero up to this load. However, it is also affected by the cycle time.


Maximum surface speed

fpm Rotating Oscillating Linear
Continuous 196 137 590
Short-term 393 275 787

Permitted surface speeds

iglide® A290 is suitable for low surface speeds. Due to the relatively high friction particularly in the low load range, the plastic bushings made of iglide® A290 heat more strongly than other bushings. With higher speeds, the friction also increases.


Figure 9.3: Maximum recommended surface pressure dependent on the temperature

Temperatures

The short-term permitted maximum temperature is 356° F.

With increasing temperatures, the compressive strength of iglide® A290 plastic bushings decreases. The diagram 9.3 clarifies this connection.

The temperatures prevailing in the bushing system also have an influence on the bushing wear. The wear increases with rising temperatures, and the influence is especially marked from 248° F temperature onwards.

Temperature limits

iglide® A290 Application temperature
Lower - 40 °F
Upper, long-term + 284 °F
Upper, short-term + 356 °F


Figure 2.4: Coefficients of friction dependent on the surface speed, p = 108 psi

Friction and wear

The coefficient of friction alters like the wear resistance with increasing load and surface speed.. With increasing speed and constant load, the coefficient of friction steadily rises. In contrast a reverse behavior is noticed at increasing load and constant speed (see Figures. 9.4 and 9.5) Friction and wear depend to a high degree on the reverse partner. Very smooth shafts increase the coefficient of both friction and wear. iglide® A290 proves to be relatively insensitive to shaft surfaces and retains a 0.4 friction coefficient µ with average surface finishes of Ra = 0.4 to 1.6 µm.

Coefficients of friction for iglide® A290 against steel
(Shaft finish = 40 rms, 50 HRC)

iglide® A290 Dry Grease Oil Water
Coefficients of friction µ 0,13 - 0,40 0,09 0,04 0,04

Figure 2.5: Coefficients of friction dependent on the load, v = 1.96 fpm
Figure 9.6: Coefficients of friction dependent on the shaft surface (1050 hard chromed)

Fig. 2.7: Wear, rotating application with different shaft materials, load p = 108 psi, v = 98 fpm

Shaft materials

The graph displays a summary of the results of tests with different shaft materials conducted with plastic bushings made of iglide® A290.

Compared to iglide® A200, the improved tribological properties of iglide® A290 are also reflected in the coefficients of wear. At low loads, the differences in the wear resistance of the combinations of iglide® A290 with different shaft materials are very distinct. Figure 9.8 shows that the advantage of hard-chromed shafts increases with rising load. This counter partner is also well-suited for pivoting applications and are frequently found in packaging machines. Other hardened surfaces are also recommended for oscillating movements, for example 1050 hardened and ground steel.

Figure 9.8: Wear with various shaft materials in rotational applications
Figure 9.9: Wear with different shaft materials, oscillating and rotating movement p = 290 psi

Important tolerances for iglide® A290 plastic bushings according to ISO 3547-1 after the press-fit.

Diameter
d1 [mm]
Shaft h9
[mm]
iglide® A290
D11 [mm]
Up to 0.5 0 - 0,025 +0,020 + 0,080
> 3 to 6 0 - 0,030 +0,030 + 0,105
> 6 to 10 0 - 0,036 +0,040 + 0,130
> 10 to 18 0 - 0,043 +0,050 + 0,160
> 18 to 30 0 - 0,052 +0,065 + 0,195
> 30 to 50 0 - 0,062 +0,080 + 0,240

Installation tolerances

iglide® A290 plastic bushings are standard bushings for shafts with h-tolerance (recommended minimum h9).

After the installation in a housing bore with the tolerance H7, the inner diameter of the bushing automatically adjusts to the D11 tolerance.


Medium Resistance
Alcohol + to 0
Hydrocarbons, chlorinated +
Greases, oils, without additives +
Fuels +
Weak acids 0 to -
Strong acids -
Weak alkaline +
Strong alkaline + to 0
+ resistant      0 conditionally resistant      - non-resistant

Figure 9.10: Influence of moisture absorption of iglide® A290 plastic bushings


Electrical properties

Specific forward resistance > 1011 Ωcm
Surface resistance > 1011 Ω

Chemical resistance

iglide® A290 plastic bushings have a good resistance against chemicals. They are resistant to most lubricants. The iglide® A290 is not affected by most weak organic and inorganic acids.

The moisture absorption of iglide® A290 plastic bushings amounts to about 1,7% in standard climatic conditions. The saturation point in water is at 7.3%, a disadvantage which must be accounted for by all means in applications in humid and wet areas.

Please contact us if there is any query about clearance design in humid applications.

Radioactive rays

iglide® A290 plastic bushings are radiation resistant up to a radioactive intensity of 3 x 10² Gy.

UV-resistant

iglide® A290 plastic bushings are resistant to UV radiation, but the tribological properties deteriorate.

Vacuum

The iglide® A290 plastic bushings can be used in vacuum only restrictedly due to the high humidity absorption.

Electrical properties

iglide® A290 plastic bushings are electrically insulating.